1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 // Framework-side code runs in this namespace. Libs from /vendor partition can't
18 // be loaded in this namespace.
19 
20 #include "linkerconfig/common.h"
21 #include "linkerconfig/environment.h"
22 #include "linkerconfig/namespace.h"
23 #include "linkerconfig/namespacebuilder.h"
24 
25 using android::linkerconfig::modules::Namespace;
26 
27 namespace android {
28 namespace linkerconfig {
29 namespace contents {
30 
SetupSystemPermittedPaths(Namespace * ns)31 void SetupSystemPermittedPaths(Namespace* ns) {
32   std::string product = Var("PRODUCT");
33   std::string system_ext = Var("SYSTEM_EXT");
34 
35   // We can't have entire /system/${LIB} as permitted paths because doing so
36   // makes it possible to load libs in /system/${LIB}/vndk* directories by
37   // their absolute paths, e.g. dlopen("/system/lib/vndk/libbase.so"). VNDK
38   // libs are built with previous versions of Android and thus must not be
39   // loaded into this namespace where libs built with the current version of
40   // Android are loaded. Mixing the two types of libs in the same namespace
41   // can cause unexpected problems.
42   const std::vector<std::string> permitted_paths = {
43       "/system/${LIB}/drm",
44       "/system/${LIB}/extractors",
45       "/system/${LIB}/hw",
46       system_ext + "/${LIB}",
47 
48       // These are where odex files are located. libart has to be able to dlopen
49       // the files
50       "/system/framework",
51 
52       "/system/app",
53       "/system/priv-app",
54       system_ext + "/framework",
55       system_ext + "/app",
56       system_ext + "/priv-app",
57       "/vendor/framework",
58       "/vendor/app",
59       "/vendor/priv-app",
60       "/system/vendor/framework",
61       "/system/vendor/app",
62       "/system/vendor/priv-app",
63       "/odm/framework",
64       "/odm/app",
65       "/odm/priv-app",
66       "/oem/app",
67       product + "/framework",
68       product + "/app",
69       product + "/priv-app",
70       "/data",
71       "/mnt/expand",
72       "/apex/com.android.runtime/${LIB}/bionic",
73       "/system/${LIB}/bootstrap",
74   };
75 
76   for (const std::string& path : permitted_paths) {
77     ns->AddPermittedPath(path);
78   }
79   if (!android::linkerconfig::modules::IsTreblelizedDevice()) {
80     // System processes can use product libs only if device is not treblelized.
81     ns->AddPermittedPath(product + "/${LIB}");
82   }
83 }
84 
BuildSystemDefaultNamespace(const Context & ctx)85 Namespace BuildSystemDefaultNamespace([[maybe_unused]] const Context& ctx) {
86   bool is_fully_treblelized =
87       android::linkerconfig::modules::IsTreblelizedDevice();
88   std::string product = Var("PRODUCT");
89   std::string system_ext = Var("SYSTEM_EXT");
90 
91   // Visible to allow links to be created at runtime, e.g. through
92   // android_link_namespaces in libnativeloader.
93   Namespace ns("default",
94                /*is_isolated=*/is_fully_treblelized,
95                /*is_visible=*/true);
96 
97   ns.AddSearchPath("/system/${LIB}");
98   ns.AddSearchPath(system_ext + "/${LIB}");
99   if (!is_fully_treblelized) {
100     // System processes can search product libs only if product VNDK is not
101     // enforced.
102     ns.AddSearchPath(product + "/${LIB}");
103     ns.AddSearchPath("/vendor/${LIB}");
104     ns.AddSearchPath("/odm/${LIB}");
105   }
106 
107   if (is_fully_treblelized) {
108     SetupSystemPermittedPaths(&ns);
109   }
110 
111   ns.AddRequires(ctx.GetSystemRequireLibs());
112   ns.AddProvides(ctx.GetSystemProvideLibs());
113   return ns;
114 }
115 
116 }  // namespace contents
117 }  // namespace linkerconfig
118 }  // namespace android
119